N-Alkylation of 2-Substituted Benzimidazole Derivatives andTheir Evaluation as Antinemic Agents

2-Substituted benzimidazole derivatives were synthesized by condensation of o-phenylenediamine with the corresponding substituted benzaldehydes and were alkylated at the nitrogen atom using C3–C10 alkyl bromides in the presence of tetrabutylammonium hydrogen sulfate as a phase-transfer catalyst and 30% aqueous potassium hydroxide as a base. The synthesized derivatives were characterized by 1H and 13C NMR and IR spectroscopy and screened for their nematicidal activity against the root-knot nematode Meloidogyne incognita by egg hatching and mortality tests. All compounds exhibited significant nematicidal potential as compared to control. The maximum egg hatching inhibition potential and maximum mortality potential were exhibited by 2-(2-nitrophenyl)-1H-benzimidazole.